The defense team, led by Judy Clarke — who has represented the man who shot Arizona Congresswoman Gabrielle Giffords and Ted Kaczynski, the “Unabomber” — wrote in a filing to a federal judge Wednesday that FBI agents are improperly dissuading witnesses to the shooting from speaking with them.

The motion says that multiple witnesses have made contact with the defense team, only to cut off communication after speaking to FBI agents.